Leave No Trace: A Novel

by Jo Callaghan Narrated by Rose Akroyd

Overview

From the bestselling author of In the Blink of an Eye comes an inventive thriller that pits algorithms against experience, logic against instinct, and one undetectable killer against two extraordinary detectives.

“Unswervingly gripping and scary, and at the same time beautifully tender and humane.”-Nicci French, author of Has Anyone Seen Charlotte Salter?

When the body of a man is found crucified at the top of a hill in the British Midlands, AIDE Lock-the world's first AI detective-and Detective Kat Frank are thrust into the spotlight as they are given their first live case. When a second body is found, the police issue an extraordinary warning to local males aged between thirty and forty years old:

¿ Avoid drinking in pubs.
¿ If you insist on going to a pub, do not leave alone.
¿ And definitely do not leave a pub with a stranger.

With the national media and local men in an uproar, Kat and Lock have to combine their instincts and algorithms to catch the killer before they can strike again.

Editorial Reviews

From the Publisher

[An] interesting dichotomy of instinct and algorithm.”—TODAY

“A thrilling ride with a twist of tech . . . this book is your next obsession.”—The Seattle Times

“Compelling.”—Criminal Element

“A smart, agile, immaculately plotted and moving thriller that is unswervingly gripping and scary, and at the same time beautifully tender and humane.”—Nicci French, internationally bestselling author of Has Anyone Seen Charlotte Salter?

“Jo Callaghan has done it again with this intricately plotted, humorous, and incredibly moving thriller.”—Laura Marshall, Sunday Times bestselling author of A Good Place to Hide a Body

“A brilliant, rapidly paced and plotted thriller. Couldn’t put it down. Another masterpiece.”—Imran Mahmood, author of Finding Sophie

“Callaghan’s riveting sequel to Blink of an Eye . . . tweaks the traditional British detective story just enough, freshening up a well-worn formula without attempting to fix what isn’t broken. This series deserves a long life.”—Publishers Weekly

“[The] big reveal is unlikely to be foreseen by even the AI-abetted reader. This thriller may feature state-of-the-art AI, but its solid craftsmanship is timeless.”—Kirkus Reviews

Kirkus Reviews

2024-09-28
The second book in the British Midlands–set Kat and Lock series reteams what may be crime fiction’s oddest couple, given that one half of the pair isn’t even human.

A man has been found dead on Nuneaton’s Mount Judd, his nude body tied to a cross and his ears cut off. To identify the victim and solve the crime, the Warwickshire police force’s DCS Kat Frank once again partners with Artificially Intelligent Detecting Entity Lock, the world’s first AI detective, who takes the form of a 3-D holographic image of a 30-something Black man. According to Professor Adaiba Okonedo—the Black scientist who created Lock and whose personal experience with racism has left her wary of cops—the idea is to use bias-free AI to “rebuild public trust and confidence in policing.” Also good: In a matter of seconds, the AI detective can do things such as “cross-check the victim’s facial characteristics, height and weight with all social media posts matching white men between twenty-five and forty ­in the Nuneaton area.” To mystery readers not predisposed to reaching for tech thrillers, the premise may sound intimidatingly geeky, but once Callaghan establishes her terms, it’s one fleet, accessible scene after another. For theStar Trek savvy, conversations between Kat and her literal-minded partner may recall exchanges with Mr. Spock (Lock: “Your entire theory is built upon nothing but your imagination”; Kat: “It’s calledempathy, Lock”). The novel’s central question—should humans fear replacement by machines?—hums throughout, but never hinders the story’s forward momentum, and the plot’s big reveal is unlikely to be foreseen by even the AI-abetted reader.

This thriller may feature state-of-the-art AI, but its solid craftsmanship is timeless.

Product Details

BN ID:	2940192471357
Publisher:	Penguin Random House
Publication date:	01/07/2025
Edition description:	Unabridged

Read an Excerpt

Atherstone, Warwickshire, 7 December, 5.55pm

He doesn’t turn to check that he’s not alone. He doesn’t cross the street to where there are more houses, more lights. He doesn’t even pretend to ring someone or hold his umbrella like a truncheon. He just walks through the night: through the absence of fear.

He doesn’t see me watching.

He stops at his front door, fumbling for the key he hasn’t gripped all the way home. He enters the hallway, not even glancing over his shoulder as he kicks the door shut.

Imagine feeling that safe.

Imagine being that stupid.

A dull yellow light splashes from his bay window, staining the frost-white drive. That’s him in the front room now, not caring to close the blinds against the dark of night and threat of snow. He stands in front of a pale-grey settee and points a remote at a large screen above the fireplace. Flickering pictures fill the room.

I bunch my frozen fists, and through the wooden shutters I spy the sleek, luxurious furniture, the high Georgian ceilings and framed paintings lining the walls. How did someone like him end up in a lovely home like that? I force out a breath so long and hard that for a moment I imagine disappearing in a puff of ice-white smoke.

It clears in seconds. And yet still I am here: alone in the cold, dark street.

The dead chill of night presses through my trainers, draining the heat from my body. I shift my weight from one freezing foot to the other. It’s not too late to walk away.

I almost do.

But then snow begins to fall, ghostly white in the dark of night.

Memories flash through me: my face distorted in a glittered bauble, the thud of distant music; snow against snow.

Blood beats fast through what’s left of my heart as I lift my face to the sky. A snowflake lands in my eye and I embrace its icy sting. I will no longer be haunted by the Ghosts of Christmas Past. I am here to reclaim my future.

I turn back towards the window, where he sucks at a bottle of beer, legs spread as he stares at the TV, oblivious to the darkness beyond.

I tuck my thumbs under my shoulder straps, feeling the weight of my rucksack and all that it contains.

Tonight, he will learn about fear.


CHAPTER ONE

DCS Kat Frank’s home, Coleshill, Warwickshire, 8 December, 5.44am

‘I’m going to count to ten,’ DCS Kat Frank warned. ‘And then I’m coming up.’ She pointed her torch at the wooden hatch above her, highlighting the broken wisps of cobwebs swaying in the chill morning air.

Silence.

Kat started counting in a clear, no-nonsense voice that she hoped didn’t betray her fear. When she reached ten, she took a deep breath and placed a hand upon the cold metal stepladder. ‘I’m coming up,’ she said, climbing higher and higher until the hatch to the attic was within reach.

Moving the torch to her left hand, she used her right to push against the wooden door and slide it across the opening. She flinched, bracing herself against something unspeakable. But there was nothing save the cold, musty smell of forgotten places and abandoned things. Kat pointed her torch into the gaping darkness and climbed the final two steps until her head and shoulders were in the attic.

She rapidly scanned the low-ceilinged room, hyper-alert to signs of attack. She swept the floor for scuttling spiders and the beams for any bats, shivering at the horror of the dark, shadowy corners in between. ‘So, the deal is, you keep the f*** out of my way,’ she shouted. ‘This is hard enough as it is, so I don’t need any of your spider shit right now.’ She swung the torch rapidly across the roof, wishing she’d worn a hat. If a spider fell on her head, she would seriously lose it.

But the attic was still and quiet.

Breathing a little easier, Kat focused her torch on the piles and piles of boxes and bags that littered the attic floor. Christ, what a mess. When they’d first moved in, she’d helped pass all the old stuff from their last house up to John on the ladder, directing him to put things where they could easily find them again. But as their growing son and expanding careers took up more and more of their time, it had been quicker for John to just throw up a bin bag of Cam’s old clothes or pop a box of discarded toys or books near the entrance, with a promise to sort it all out later.

But for John, there was no ‘later’. And if there had once been a system to this chaos, then it was lost to her now. Kat sighed. How the hell was she supposed to find the Christmas decorations among all of this? She pointed the torch into the far right-hand corner, where things still looked relatively organised. There was something lemon-and-pine-coloured, wrapped carefully in clear sheets of plastic.

Oh my God. Cam’s Moses basket!

Instinctively she turned, but of course, there was no one else to share the recognition with. In fact, there was not a single other person alive who’d remember how she and John had agonised over which basket to buy, spending much more than they could afford, only for Cam to refuse to sleep anywhere but in their arms.

She blinked away the shot of self-pity and firmly moved the torch away from Cam’s baby bath, his cot bed and the bag of his first clothes. She couldn’t deal with them now. She was just here for the Christmas decorations. Logic told her that they shouldn’t be too far from the entrance, but then logic hadn’t been John’s strong point. ‘Where would you have put them?’ she muttered.

She spotted a large plastic box on her left that looked familiar and leaned over to drag it closer. The box moved, and a sudden flutter of tiny black wings exploded in her face.

Kat screamed. She leapt back, nearly losing her footing as she half-scrambled, half-fell down the stepladder, dropping the torch as she beat at her clothes and hair to get them off.

Panting, she stared at the landing floor, littered with tiny black things. She leaned closer. Poked one with her finger. Plastic. The ‘wings’ were just tiny pieces of shredded black plastic. Kat frowned. All those bin bags they’d thrown up there over the years must have disintegrated and fallen apart. She slid to the floor, her movement causing the scattered pieces to float up around her like confetti. With her elbows on her knees, she plunged her hands into her hair. Jesus, what had she become? A perimenopausal insomniac who decides to get the Christmas decorations out of the attic at the crack of dawn; someone who talks to spiders and is terrified by a bloody bin bag.

She cursed her husband. Why hadn’t John sorted the attic out? Why had he put things into black bin bags, for God’s sake? Why hadn’t he ever got round to putting a proper frigging light in the attic?

Kat buried her face in her hands, on the verge of sobbing. Why did he have to die?

She jumped as her phone alarm went off: 6.15am. Time to get ready for work and pretend she was a completely normal, functioning human being. She clicked on her calendar, to remind herself what time she was due in. Shit. It was her quarterly review with her boss McLeish today. Kat scrubbed her face with her hands. She knew she was on the edge. She could feel the sinkhole beside her, the pulling gravity of grief. And with Cam away at university, there was so little left to hold on to.

She rose to her feet, brushing off the last bits of plastic that still clung to her pyjamas, mind sharpening with every second. She had to convince McLeish to give her a live case today.

She needed something solid to grasp on to or she would sink without trace.

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